Brown mordant dye.



Patented August 9, 1904.

UNITED STATES PATENT OFFICE.

-AUGUST LEOPOLD LASKA, OF OFFENBACH-ON-THE-MAIN, GERMANY, ASSIGNOR TO THE FIRM OF K. OEI-ILER, ANILIN- & ANILINFARBEN FABRIK, OF OFFENBACH-ON-THE-MAIN, GERMANY.

BROWN MOFIDANT DYE.

SPECIFICATION forming part of Letters PatentNo. 767,070, dated August 9, 1904.

Application filed June 16, 1904. Serial No. 212,795. (No specimens.)

To (ti/Z whmn it may concern:

Be it known that I, AUGUST Lnoronn LAsKA, doctor of. philosophy, chemist, a resident of 5 Gerberstrasse, Offenbach-on-the-Main,Grand Duchy of Hesse, German Empire, have invented new and useful Improvements in Brown Mordant Dyes, of which the following is a specification.

In the application for Letters Patent filed on my behalf on the 13th day of April, 190%, Serial No. 202,909, there are described mordant dyes which result from coupling sulfoconjugated diazonaphthalenes with m-oxydiphenylamin. My further investigations have led to the discovery that still more valuable dyestuffs are obtained by combining the sulfonic acids of heteronuclear diazonaphtholes with m-oxydiphenylamin. These dyestuffs yield. on wool when dyed in an acid-bath orange to violet shades, which turn into reddish brown to brownish violet on a subsequent treatment with chromium compounds acting as oxidizing agents and which are distinguished by a prominent fastness to light, milling, and potting. In order to enable a most easy course of the formation of the dyestufl', it is advisable to carry out the combination of the diazo-naphthol-sulfonic acid with the m-oxydiphenylamin in a weakly-acid solution.

The following examples may illustrate the manner in which my invention is best carried out: Diazotize 59.65 parts of 2.5 amide napl1thol-7-sulfonic acid by means of one hundred and twenty-live parts of hydrochloric acid of 20 Baume and nineteen parts of sodium nitrite. At 15 centigrade run into the suspension of the diazo compound a solution of forty-nine parts of m-oxydiphenylamin in 69.5 parts of sodium lye of 36 Baum and three hundred parts of water, then add one hundred and thirty-six parts of sodium acetate. As soon as no more diazo compound is indicated by a test portion neutralize with soda, heat the whole on to about 70 centigrade, salt out, and dry. The dyestufl thus obtained forms a brownish-black powder, dissolving in water a yellowish brown and in concentrated sulfuric acid with a vi0 let color. The aqueous solution is rendered somewhat darker on adding sodium lye. On adding hydrochloric acid the dyestufl separates as a reddish-brown precipitate.

In the following table I shall describe the tinctorial properties of some coloring-matters obtainable by the above process, viz:

D cs 'ool-- Dyestuff from m-oxydiy Now, what I claim, and desire to secure by Letters Patent, is the following:

1. The process of making mordant-dyeing monoazo dyes consisting in combining in an acid solution m-oxydiphenylamin with the sulfonic acids of heteronuclear diazonaphthols, substantially as described.

2. As new articles the coloring-matters which result from combining the sulfonic acids of heteronuclear diazonaphthols in an acid solution with m-oxydiphenylaminwhich form blackislrbrown powders, dissolve in sulfuric acid to a violet in water to a yellowishbrown to brownislrviolet solution, from which hydrochloric acid precipitates the dyestufi and which yield on wool on dyeing from an acid-bath orange to violet shades, being converted into reddish brown to brownish violet on subsequently treating with chromium compounds acting as oxidizing agents, substantially as described.

3. As new articles the coloring-matters, which result from combining the sulfonic acids of heteronuclear beta-diazo-alphanaphthol, which form blackish-brown powders, dissolve in concentrated sulfuric acid to a Violet, in Water to a brownish solution, from my invention I have signed my name, in pres- Which hydrochloric acid precipitates the dyeence of two Witnesses, this 4th day of J une, 10 Stuff which dye 0n WOOl from an acid-bath 1904.

orange to reddish-brown shades being con- AUGUST LEOPOLD LASKA 5 verted into a dark broWn .on subsequently treating with chromium compounds acting as Witnesses:

oxidizing agents, substantially as described. EVA SATTLER,

In testimony that I claim the foregoing as ASKERO STANDHARDT. 

